LLDSIMEX 10 Pairs Precision Parallel Set 1/8" Thin Steel Dimensions: 7.3' 8.6' 2.4' Parallelism:+/- .0002", Paired +/- .0002" in Height Made of high grade alloy steel, hardened and ground. 2 holes in each parallel Measurements: 6" long x 1/8" thick Hardness: 54-58 HRC /8" from 1/2" to 1-5/8" Set includes a pair of each height: 1/2, 5/8, 3/4, 7/8, 1, 1-1/8, 1-1/4, 1-3/8, 1-1/2 and 1-5/8 Package Include:10 x Parallels